CYBERLANG
A cyberpunk RPG that teaches a real language (Japanese first) by "infecting" the game itself — a digital contagion progressively overwrites the UI, dialogue, and your character's thoughts into the target language. The localization is the boss fight.
You start in 100% English. Then the Linguavirus — a digital contagion loose in the game world — begins overwriting the UI, dialogue, signage, and eventually your own character's inner monologue into Japanese. To advance, you have to actually understand it. The fiction is the difficulty curve.
The repo pairs a deep design exploration (vision, lore, mechanics, pedagogy, and a list of 100 open questions) with a runnable Expo scaffold implementing a vertical slice, "First Night in Neo-Kanda." Under the hood: a pure-reducer story engine, an FSRS-lite spaced-repetition scheduler, and a bilingual furigana text renderer.
A headless npm run play mode drives the real reducer to report branch divergence, overwrite/recovery rates, and difficulty "friction walls" — playtesting the pedagogy without opening the app.